Two paragraphs from that post....they seem to contradict...
Why Is 70% the Most Effective Concentration of Isopropyl Alcohol for Disinfection?
Isopropyl alcohol, particularly in solutions between 60% and 90% alcohol with 10 – 40% purified water, is rapidly antimicrobial against bacteria, fungi, and viruses. Once alcohol concentrations drop below 50%, usefulness for disinfection drops sharply. Notably, higher concentrations of alcohol don’t generate more desirable bactericidal, virucidal, or fungicidal properties.
Technically, all grades of rubbing alcohol containing 68% -72% isopropyl alcohol fall under the “rubbing alcohol” namesake for household use. Isopropyl alcohol concentrations >91% volume fail to provide bactericidal efficiency and are less effective for antiseptic use, thus its distinction as “rubbing alcohol” is not warranted and may cause confusion.
LOL!
Millenials that never learned the difference between “per cent” and proof”...
BNO Newsroom
@BNODesk
NEW: Officials in Sunnyvale, California, say a 72-year-old person has died despite officers performing CPR. It was later learned that this person had been on a cruise ship with 2 people suspected of having coronavirus. No further details yet.
91% straight is going to dry your skin out like a long day at the beach. Add a little bottled water to it to take the % down a tad and decrease flammability. (might add some aloe gel too, if you’re going to use it as a hand sanitizer)
The CDC website recommends 70-91%.
Why not use 95 or 99%?
When you sear a roast, you’re protecting the juices inside the meat. The higher percentage alcohol you use, the faster you’re going to sear or seal the outside of a cell and the alcohol isn’t going to get inside that cell. Water prevents searing and acts as a tool for the alcohol to enter the cell. The pressure difference between the water on the outside and pressure inside of the cell sucks that alcohol right in. Water also has a static charge that will help Velcro onto both the virus and the alcohol, reducing evaporation time and giving the alcohol more time to do its thing.
RECIPE - reducing 91% to 70%
In cups, from eHOW.co.uk
Measure out one cup of 91 per cent rubbing alcohol, and pour it into the plastic container.
Add one-third of a cup of water and stir to mix the solution. The solution is now 70 per cent rubbing alcohol.
In grams (from answers.com)
measure 77 g of 91% alcohol and add 23 g of water.